Apparatus for applying heat to vessels used in hydrocarbon oil conversion



Feb. 12, 1935.v f E. F. NELSON 17,990,878

APPARATUS FOR APPLYING HEAT TO VESSELS USED IN HYDROCARBON OIL CONVERSION Original Filed Sept. 9, 1929 Zlzu n mlazz,

Patented Feb. 12, 1935 PATENT o r-FICE` APPARATUS FOR APPLYING HEAT TO VES- SELS USED IN HYDROCARBON OIL CON- VERSION Edwin F. Nelson, Chicago, Ill., assignor to Universal OilProducts Company, Chicago, Ill., a corporation of South Dakota Application September 9, 1929, Serial No. Renewed January 26, 1953? 2 clams. (01.,196-111) Y This invention relates to improvements in the application of heat to vessels used in hydrocarbon oil conversion, and has for one of its principal objects, means for eiciently and uniformly 5.: heating hydrocarbon liquid passing thereinto.

In one embodiment, the invention has been designed particularly for use in the cracking of hydrocarbon oils under relatively high temperature. In a more specific embodiment, it is especially applicable to those systems of the tube and drum type using an enlarged reaction chamber wherein expansion and separation of vapors from nonvaporous products `of reaction occurs. In systems of this general type the reaction chamber '1functions as a time zone, and 'according to my invention, I'have designed an efficient structure for applying heat to said chamber.

One embodiment of my invention comprises a closed vessel or shell, the lateral Walls of which 0' are entirely or partially surrounded by a jacket throughwhich a heating. medium is adapted to pass. The interior ofr the vessel is provided With an annular Wall or Walls, concentrically dis` posed relative tothe Walls of the vessel, pro-` viding an annular Zone or Zones,'which communicate. with the interior of the vessel proper, or communicate successively with each other. The fluid initially admitted tothe vessel is adapted to iirst pass through said annular zone, owing v0" therein in a turbulent state in proximity to the heated outer walls of the vessel, and thence into the'interior proper of the vessel, from which latter non-vaporous liquid may be drawn from the lovv-J` er portion thereof, While separated vapors may l pass out through an outlet at the top. 1

VI-Ieretofore, it has been proposed, in heating a reaction or separating vessel of thecharacter described, to provide a jacketsurrounding ther the iilm of liquid or vapor immediately adjacent; the Ah'eatedvvalls of the vessel Will absorbV more S heat than is desirable, While the remaining liquid 'or vapor in the interior of the vessel will prot little by the application of the heat.

According' to my invention, I propose to heat the outer walls of the vessel, but in admitting the 553" liquid or vapors to be processed into the vessel,

they are initially passed to and through said annular zone Within the vessel adjacent to, and concentric with, the Walls of the vessel. Due to the velocity of the material entering said annular zone, and the comparatively restricted area of the zone, the material assumes a turbulentV state Within the zone, Which insures an eflicient and uniform heat transfer from the heated Walls of the vessel to the liquid or vapors. No quiescent film is permitted to remain upon said inner walls because of the violent motion of the liquid or va.- pors, and hence, undesirable overheating and consequent formation of objectionable amounts of coke is prevented. The Vliquid or vapors may then enter the interior of the vessel Where separation of vapors from non-vaporous material may take place. Y

It will be understood that the invention in its broadest aspects contemplates the use of one or more of said concentric zones, that is, a plurality of concentric Zones may be provided, one Within the other, wherein the liquid or vapor flow through adjacent zones maybe opposite, if desired.

In the drawing, Fig.V 1 is a diagrammatic side elevational View, partly in section, showing ap-` paratus suitable for carrying out a process for cracking hydrocarbonoils for which this invention isl particularly adapted.`

^ Fig. 2 is an enlarged detail cross-sectional View showing the arrangement of a reaction chamber comprising one embodiment of myinvention.

AReferring more particularly to the drawing, and. in particular to Fig.v 1 the charging stock to be processed may be delivered from storage through from line 3 may pass into dephlegmator 6 where.

it assists in condensation and fractionation of the vapors entering the bottom o f the dephlegmator.. Reflux condensate collecting in the lower part of the dephlegmaton' together with unvaporized charging stock, passes out of the bottom thereof through lines 7 and 8 tothe suction side of `hot o il pump 9, from which it is forced through line 10, controlled by valve .11, throughheating coil 1'2 disposed in a conventional furnace 13. The cil from heating coil l2 leaves through transfer line 14, in which may be interposed valve 15, discharging into reaction chamber 16. The heated hydrocarbon mass entering reaction chamber 16 separates therein into vapors'andnon-vaporous products, the vapors passing out through vapor outlet line 17, in Which may be interposed valve 18, while the non-vaporous products pass to the bottom of the chamber to be withdrawn through residue drawoff line 19, controlled by valve 20, to a cooler (not shown), or if desired, may be further processed. 'I'he vapors leaving chamber 16 through line 17 may be passed into the lower portionof dephlegmator 6, wherein suiciently converted portions are separated from insuiciently converted portions, the latter collecting as reflux condensate to be returned for retreatment together with the raw oil, as heretofore described. Y

'I'he vapors remaining unconden'sed after pass-1r ing through dephlegmator 6, which comprise those vapors which are sufficiently converted, pass out of the dephlegmator through vapor line 21, controlled by valve 22, into condenser'23. These vapors 'consist of non-condensable gases and condensable distillate, the condensable Y tillate being condensed in condenser 23. `The mixture of condensed liquid and non-condensable gasleaves the condenser through line 24, inwhiclr mayA be Vinterposed valve 25, passing to, receiver 26 .where a separation of 4the gases and distillate occurs. kThe Ypressure at which this separation occurs. maybe controlled by the rate at which4 gas passes through gas outletline 27, controlled' by'valv'e 28, into a gas separator 29 maintained at llower pressure. The liquid level inV receiver y26 may be controlled by the rate of withdrawal of distillate through distillate drawoff line 30, in which may be interposed'valve 31, line 30 connecting vto the bottom of the gas separator 29. Non-condensable gas from gas separator 29 may pass out through outlet line 30', Acontrolled by valve 31', from which point it may pass to storage or to any other'point of utilization.

The distillate in the gas separator 29 may be` withdrawn through liquid drawoif line 32, controlledby valve 33, and may be passed to storage. Regulated portions ofthe distillate collecting in receiver 26 may be withdrawn through distillate recirculating line 34 leading to the suction side of distillate recirculating pump 35, from which point regulated portions of the distillate may be forced through line 36, controlled Vby valve 37, to the top of dephlegmator 6 to aid in the condensation andfractionation of thefvapors leaving the' dephlegmator. v

It may sometimes be found desirable not to feed all of the charging stock to the top of dephlegmator 6, in which case. valve 4 may be partially or totally closed and valve 38 partially orf totally opened, Vpermitting the passage of a part or all of the charging stock through branch 39 and'line 8 to the suction sideof hot oil pump 9.- The oil passing through coil 12, is heated infurnace 13, provided with burner 40, which may utilize oil, gas, coal, coke orv other fuel. Combustion gases from burner 40 may pass from com-v bustion 'chamber 41 through bank 12. which may be heated as found desirable either by radiation,

' convection or'conduction.A After passing through heating coil 12, the combustion gases mayv continue their'passage through vduct 42 and up through stack 43. The draft on furnace 13 mayV y be controlled by damper 44.

Referring more particularly to Fig. 2, 53 designates a closed'cylindrical vessel surrounded by a jacket 47 providing Aan annularv space 47vthrough' which a lheating medium such as heated combustiongases or the like, maybe circulated. A portionof the vfluegases passing through stack 1,43 may be by-passed through duct 45, controlled by damper 46-into the lower portion of heating enclosure 47 which surroundsthe reaction cham.-

ber. The flue gases may leave heating enclosure 47 through duct 48, controlled by damper 49, into stack 43. The relative proportions ofV flue gases going Vdirect up the stack to the heating enclosure 47 may be controlled by propermanipulation of dampers 44, 46 and 49. n f

kThe interior of the vessel 16 may be vprovided with an annular plate l51 whichis preferablyV Y spaced from, and disposed concentric with, the walls 53 of the vessel 16, for substantially the lengthV thereof,providing an annular zone v50 iwhich A"communicates with the-interior of V the vessel at the lower portion thereof, as illustrated. The heated hydrocarbon mass from coil 12 enters the'. 'reaction chamber 16 throughv linej 14 where it passes through the annular compartment 50. lThe mass then passes down underneath the base ofpartition 51, the separated vapors then` f, l passing up through the central opening 52 from Ywhence they leave through line 17.

Theilue gases beingat a highertemperature than themetal wall 53 ofreaction chamber 16 heatsaid wall, which in turn imparts thevheat;

toV the` oil orA Avapors passing through annularv space 50, which, due to its relatively'V smallv crosssection, causes the oil or vapor to be sufciently turbulent so as not to cause overheating of the film layer next to wall 53. While only one concentric partitionis shown, itris to be understood;

that a series of these Vpartitions may be used to` force the oilor vapors up and down through re s action chamber 16 if found desirable.

To prevent heat losses from reaction chamberv 16, insulation may be placed on Ythetop and bottom of said chamber, as illustrated in cross-section at54. It has heretofore beenthe practice to permit the oil and vapors entering through line 14 to pass unrestricted to either line 17 or line 19, heat being applied to vthe reaction chamber.

16 by the use of heatingV enclosure 47. In utiliz- Ving my invention, the heated hydrocarbon mass.

may be introduced into the reaction chamber soV as vto obtaina maximum velocity and considerable turbulence so as to effect suilcient heatV l transfer from heatedrwall '5B-to the vapors* and4 oil passing through annular space 50. This turi bulence breaks up the Vflmnext to wall 53 and thu'sprevents overheating of any. portion of theV oil and the consequent formationy of coke or .like

undesirable substances. f

I am aware thatA many details of x'nyv invention. For example, the-distance between the walls; 53 and51 may be varied but preferably this distance should be so chosen asY toof the vessel and being concentric with and spaced* from the vertical wall. of Vsaid vessel thereby form.- ing an .annular passageway with saidwall, the interior cross-sectional area enclosed byj said batllebeing substantially greater thanthecrosssectional area of said passageway, means'forV in. Vtroducing heated oil to the upper portion of *said ofV construction.` may bevaried without .departing from. the spirit.

annular passageway, a residue outlet atA the lower V portion ofv said vessel, means for removing vapors from the upper interior portionenclosed by said baille,` ajacket surrounding the exterior of` Iii Wall, and means for passing a heating medium through said jacket.

2. An oil cracking apparatus comprising a heating coil, disposed within a furnace, a vertical cylindrical reaction chamber of substantially uniform cross-section from top to bottom, a cylindrical baille dependingiromthe top of said chamber to a point adjacent the bottom thereof and concentric with and spaced from the vertical wall of the chamber, said baille forming with said wall an annular restricted passageway of smaller cross-section than the interior portion enclosed by said baille, means for passing heated oil from said coil into the upper portion of said passsageway, means for removing residue from the lower portion of said chamber, means for removing vapors from the upper interior portion enclosed by' said baiiie, a. jacket surrounding the exterior of said wall, and means for passing' a regulated portion of the waste combustion gases from said furnace through said jacket.

EDWIN F. NELSON. 

